Is Bitter Medicine for Cyprus a Cure for the Euro Zone?

The euro zone's decision to force Cyprus to impose losses on bank depositors as a condition of its €10 billion ($13 billion) bailout has inevitably provoked a furious reaction in some quarters.

There have been claims it marks a turning point in the crisis, the moment at which the euro zone implicitly confirmed that a euro in a peripheral euro-zone bank account isn't worth the same as a euro in a core country bank account. And that...